Morphology of coronary artery lesions assessed by virtual histology intravascular ultrasound tissue characterization and fractional flow reserve

Abstract

Fractional flow reserve (FFR) is an index of the physiological significance of a coronary stenosis. Patients who have lesions with a FFR of >0.80, even optimally treated with medication, have however a MACE rate ranging from 8 to 21%. Coronary plaques at high risk of rupture and clinical events can be also identified by virtual histology intravascular ultrasound (IVUS-VH) as plaques with high amount of necrotic core (NC) abutting the lumen. Aim of this exploratory study was to investigate whether the geometry and composition of lesions with FFR ≤ 0.80 were different from their counterparts. Fifty-five consecutive patients in whom FFR was clinically indicated on a moderate angiographic lesion, received also an imaging investigation on the same lesion with IVUS-VH. Data on plaque geometry and composition was analyzed. Patients were subdivided in two groups according to the value of FFR (> or ≤0.80). Lesions with a FFR ≤ 0.80 (n = 17) showed a slightly larger plaque burden than those with FFR > 0.80 (n = 38) (54.6 ± 0.7% vs. 51.7 ± 0.7% P = 0.1). In addition, they tend to have less content of necrotic core than their counterparts (14.2 ± 8% vs. 19.2 ± 10.2%, P = 0.08). No difference was found in the distribution of NC-rich plaques (fibroatheroma and thin-capped fibroatheroma) between groups (82% in FFR ≤ 0.80 vs. 79% in FFR > 0.80, P = 0.5). Although FFR ≤ 0.80 lesions have larger plaque size, they do not differ in composition from the ones with FFR > 0.80. Further exploration in a large prospective study is needed to study whether the lesions with FFR > 0.80 that are NC rich are the ones associated with the presence of clinical events at follow-up.

The Association Between Quantitative Flow Ratio and Intravascular Imaging-defined Vulnerable Plaque Characteristics in Patients With Stable Angina and Non-ST-segment Elevation Acute Coronary Syndrome

“…However, the majority of the included lesions (89%) were from patients with stable coronary artery disease and this association needs to be verified in a broader spectrum of patients. Additionally, discrepant results were reported in previous studies examining whether plaque characteristics assessed by OCT ( 14 – 16 ) or VH-IVUS ( 17 – 20 ) had an impact on coronary hemodynamics. Hence, the association between coronary physiology and OCT/IVUS-defined plaque vulnerability remains elusive and warrants more evidence.…”

“…Several studies have examined the relationship between VH-IVUS-defined plaque features and physiological severity in coronary stenosis; however, their results are inconsistent. Most of the studies suggested that FFR correlated with IVUS-MLA and plaque burden but not with plaque compositions and TCFA ( 17 – 19 ). Conversely, a recent study by Sezer et al ( 20 ) showed that necrotic volume, TCFA, and positive remodeling may have an impact on the hemodynamic outcome of intermediate lesions.…”

Association Between Blood Glucose Variability and the Characteristics of Vulnerable Plaque in Elderly Non-ST Segment Elevation Acute Coronary Syndrome Patients

“…The vulnerable plaque is characterized by a large lipid necrosis core and a thin fibrous cap formed by macrophage infiltration and it is closely related to cardiovascular events. 12,13) Vulnerable plaques could be identified by noninvasive and invasive methods. As a kind of invasive examination with good penetrability, VH-IVUS could be used to distinguish and measure the content of fibrous, lipid, necrotic, and calcium constituents.…”

Evolution of intravascular assessment of coronary anatomy and physiology: from ultrasound imaging to optical and flow assessment

“…However, other recent data in small cohorts demonstrate that physiologic lesion assessment with FFR does not correlate beyond plaque burden with plaque composition or lesion phenotype as assessed by VH-IVUS [47]. TCFA + PB ≥70% + MLA ≤4 mm 2 ≤4·0 mm 2 Figure 3 Data from the PROSPECT trial.…”